The 'What Being the Parent of a New Baby is Like--Revised' (WPL-R) is an instrument designed to measure adaptation to parenthood. In the process of pilot testing and validating the WPL-R in a postpartum Dutch population, we became aware of the potentially sensitive nature of the measure. Despite the ethics committee waiving the invasive nature of the measure, we conducted a survey to explore its possible effect on women's thoughts and emotions by using the Positive And Negative Affect Schedule (PANAS) to measure changes associated with completion of the WPL-R. Two hundred and fifteen questionnaires were returned. Our findings indicated a change in PANAS scores, implying an intervening effect when using the WPL-R, in research. This raises the question of whether it is acceptable to use a questionnaire with postpartum women without any knowledge of the possible effect it may have, even though the ethics committee has approved the study and considers the measure to be non-invasive.